The discussion below is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.
The performance and operational life of hydraulically operated or powered systems, such as but not limited to hydraulically operated actuator based material and component test systems, are directly dependent upon the quality of hydraulic fluid used in such systems. In general, fluid deterioration and contamination are of particular concern. Fluid deterioration starts as “additive deterioration.” Additives present in hydraulic fluid are particularly susceptible to chemical and physical changes arising from mixing fluids, entrapped air and high temperatures. Additive deterioration then leads to breakdown of the hydraulic fluid. On the other hand, contamination of the hydraulic fluid such as when the fluid contains hard metallic particles can severely damage hydraulic pumps and servovalves, particularly when the particle size is larger than the clearance between lubricated surfaces.
Periodic sampling and then testing of the hydraulic fluid used in a system contributes significantly to increased uptime and better performance of hydraulic systems. Sampling includes drawing off of a small portion of the hydraulic fluid present in the system into a small vessel such as a glass bottle. Problems however can arise if the sample itself becomes contaminated, for example, due to the location at which the sample is taken from the system, prior contamination of the sampling equipment and/or sample container, or other mistakes made by the sampling technician. In view that maintenance of the system such as removing and replacing the hydraulic fluid in the system will be determined based on testing of the sample taken, it is important that the hydraulic sample is a true and accurate representation of the system hydraulic fluid and that it be particularly free of any extraneous contamination.